EP4200459B1 - Pvd process and device therefor - Google Patents

Description

The invention relates to a PVD process and a device therefor.

It is known to coat substrates by vapor deposition. B. Schuhmacher ("Innovative steel strip coatings by means of PVD in a continuous pilot line: process technology and coating development", Surface and Coatings Technology 163-164 (2003) 703-709 ) describes a PVD coating device that has an optimized nozzle design. The coating is carried out in a production line by guiding the substrate to be coated along the nozzles. This produces layers whose layer thickness varies by ≤ ±10%.

The US8436318 B2 describes a PVD system that uses rigid sheets as electrostatic shielding elements. The gas flow is only allowed to pass in one direction by electrostatically shielding the opposite side of the chamber. There is no specific control of the gas flow. Homogeneous layers cannot be produced using this method. With narrower strips, problems arise in the edge layer. Wide strips cannot be produced.

From the EP 2231895 A1 A coating device is known in which the layer thickness is adjusted using guide plates. The guide plates are arranged at equal distances from one another and form a screen-like shield for the substrate. Their axis of rotation allows adjustment in two positions: open or closed. However, this device does not contain any special control, so the device does not achieve a homogeneous layer thickness distribution. In addition, a considerable flow resistance is generated when the flaps are closed. This increases energy consumption and is therefore associated with increased production costs. In addition, high flow resistance leads to a build-up of particles and thus to high particle concentrations.

1. a) Auf ebenen Metalloberflächen, die in Hochvakuum und/oder bei hohen Temperaturen behandelt wurden;
2. b) Wenn das Molmassenverhältnis der Gas- und Substratmoleküle klein ist;
3. c) Wenn die Translationsenergie der Gasmoleküle im Vergleich zur Oberflächenenergie mehr als ein Paar Elektronenvolt beträgt.

The phenomenon of diffuse surface reflection is well known in the art and occurs particularly in the following cases:

1. (a) On flat metal surfaces treated in high vacuum and/or at high temperatures;
2. b) When the molar mass ratio of the gas and substrate molecules is small;
3. c) When the translational energy of the gas molecules compared to the surface energy is more than a couple of electron volts.

If the gas flow in a PVD system exhibits diffuse reflection behavior, the flow in the area of the walls is reduced. If there is diffuse surface reflection on the side walls of the coating chamber, the layer thickness on the substrate in the edge area decreases significantly, since the atoms diffusely reflected on the surfaces of the side walls hinder the flow in the direction of the substrate. In addition, the material consumption increases in order to achieve the desired layer thickness in the edge area. As a result, the diffuse reflection behavior leads to a reduction in the efficiency of the evaporation process.

To reduce the effects mentioned, complex coating systems using complex mechanical systems have been used up to now. However, this created high flow resistance and the desired homogeneity of the coating could not be ensured.

It is also known to coat substrates using hot-dip galvanizing or electrolytic coating. However, the choice of alloys is very limited.

The narrow selection of alloys in hot-dip galvanizing is determined by the melting temperature of the coating alloy. This means that only substances whose melting points are not too far apart can be deposited.

In the case of electrolytic coating, the choice of alloy is limited by the nature of the substances, for example by solubility and/or polarity. Since the electrolytic deposition takes place in an aqueous medium, an electrolytic process cannot be used for certain substances, such as organic molecules or aluminum.

The object of the invention is to provide a coating process which enables homogeneous layer thicknesses in strip-shaped substrates, in particular variably adaptable with respect to the strip width, with a maximum possible composition variation and with high energy efficiency.

The problem is solved with the features of claim 1.

Advantageous further developments are identified in the dependent subclaims.

A further object of the invention is to provide a device for carrying out the method, with which homogeneous layer thicknesses are made possible for strip-shaped substrates, in particular homogeneous layer thicknesses for different substrate widths while minimizing the flow resistance, wherein the device has a simple and robust construction and has a high energy efficiency.

The problem is solved with the features of claim 10.

Advantageous further developments are identified in the dependent subclaims.

According to the invention, a PVD method and a device for carrying out the method are created. It has been found that the PVD method according to the invention is particularly energy-efficient and cost-saving. The energy required for other coating methods is distributed in the case of hot-dip galvanizing, PVD and electrolytic coating as 1:10:100. Thus, the PVD coating method according to the invention uses ten times less energy than an electrolytic coating method.

The method and the device according to the invention serve to coat substrates, which are in particular strip-shaped substrates. These are, for example, rolled metal strips, such as steel strips. The coating is carried out in particular for the deposition of metallic layers on the substrate or strip surface, whereby the metallic layer is in particular a corrosion protection layer. The corrosion protection layer can be a cathodically effective layer, such as a coating of Zinc or zinc-based (i.e. made of a metal that is electrochemically less noble than the substrate) or a barrier protection layer, e.g. an aluminum layer or an aluminum-based layer. But other metallic elements or combinations of the layers mentioned with the metallic elements mentioned, in particular magnesium, nickel, chromium, silicon and their alloys, can also be deposited. With regard to corrosion protection, layer combinations of zinc, magnesium and aluminum can be used, for example.

In particular, the method and the device relate to a strip coating that takes place in a continuous process and can be integrated inline in a processing process for a metal strip, preferably a steel strip. This enables a continuous coating of a substrate, in particular a strip-shaped substrate.

The inventors have recognized that the requirements for innovative coating devices and in particular for flap systems consist of the adjustment of the layer thickness on the top and bottom of the substrate, a high uniformity of the layer and a low flow resistance at different bandwidths.

According to the invention, it was recognized that the reflection behavior of the surfaces of the coating chamber and the flaps has a significant influence on the resistance of the gas flow and the layer thickness on the substrate. By optimizing the angle of attack on the flap system and adjusting the flaps, it is possible to generate homogeneous flow resistances or homogeneous flows and thus layer thicknesses, especially with different strip widths. Different strip widths can exist if either the strip has different widths over the length of the strip - this is the rarer case - or if after an entire coil (spooled metal strip) with a certain strip width has passed through, the next coil has a different, different strip width. This can very often be the case in production and a method or device which enables this changeover or adjustment to a given strip width in a simple and robust manner is advantageous in terms of production technology.

According to the invention, single-part or multi-part flaps are used as flow obstacles. Flaps in the sense of the invention are therefore not to be interpreted as a binary system (open or closed), but rather they act as guide vanes in the sense of a guide device.

A low flow resistance is set by a flap configuration adapted to the substrate width and desired layer thickness, so that the pressure loss when passing through the flaps is much lower than with conventional PVD coating systems. The gas pressures occurring in the system are therefore much lower than, for example, with a nozzle-based coating system.

In industrial production, the most homogeneous layer thickness possible is usually desired across the substrate width and length as well as the top and bottom, e.g. 3 µm layer thickness of zinc on the steel strip on the top and bottom of the steel strip. However, the invention also makes it possible to specifically control the layer thickness distribution using the control device so that, for example, the layer thickness on the top of the substrate is 5 µm and on the bottom 1 µm (or vice versa). An approximately stepped distribution of the layer thickness across the substrate width is also possible, whereby the minimum width of a "step" can be determined by the number and length of the flap wings.

The steam pressure is controlled by regulating the flow resistance, which can be changed by adjusting the flap angle of attack.

The vapor pressure p(T) is calculated according to the Clausius-Clapeyron equation from the enthalpy of vaporization ΔH and the universal gas constant R for a certain temperature T : $$\mathit{ln}\frac{p\left(T\right)}{p_1}=\frac{\mathrm{\Delta }H}{R}\left(\frac{1}{T_1}-\frac{1}{T}\right)$$

By adjusting the vapor pressure, the deposition rate r can be controlled, which is calculated taking into account the 1-dimensional Maxwell-Boltzmann distribution for a vapor with the molar mass M: $$r=\mathrm{<figure-callout\; id="2"\; label="p\; M"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">p</figure-callout>}{\left(\frac{M}{}\right)}^{}{\left(\frac{}{2\mathit{\pi RT}}\right)}^{1/2}$$

The following applies to the particle density ρ : $$\rho =\frac{\mathit{pm}}{\mathit{RT}}$$

If the substrate is to be coated at a rate (mass/area/time) of r , the flow velocity v is: $$v=\frac{r}{\rho }={\left(\frac{\mathit{<figure-callout\; id="2"\; label="RT"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">RT</figure-callout>}}{2\mathit{\pi M}}\right)}^{1/2}$$

, mit einer Zeitkonstante τ ab, welche Auskunft darüber gibt, wie lange es dauert, bis eine Beschichtungskammer mit einem Volumen Vgefüllt wird: $$\frac{p.M}{R.T}V=A.\rho .v.\tau$$

After changing the flap angle of attack, the flow state changes. The difference D between the old and the new steady flow state decreases according to $D=e^{-\frac{t}{\tau }}$

, with a time constant τ, which provides information about how long it takes until a coating chamber is filled with a volume V: $$\frac{p.M}{R.T}V=A.\rho .v.\tau$$

The time constant τ results from the above relationships: $$\tau =\frac{\mathrm{<figure-callout\; id="2"\; label="V\; A"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">V</figure-callout>}}{A}{\left(2\pi \frac{M}{\mathit{RT}}\right)}^{1/2}$$

For example, the time constant τ for a chamber volume of 20 m ³ and an evaporator surface of 4 m ² at 500 °C is approximately 0.04 s. If the steady state is to be reached by 99%, the time t is required, which in this case is 0.2 s: $$t=-\tau .\ln \left(0.01\right)$$

During the coating process, the initial flap configuration is set according to a numerical simulation of the PVD coating. The desired mean values of the layer thickness on the top and bottom of the substrate are designated as D _OS and D _US . During the coating, layer thickness measurements are carried out. Once the mean values of a traversing measurement after the coating chamber with dos and dus are available, first the belt speed v and/or the evaporator power P are adjusted to v' and P', whereby either v or P or both can be varied according to: $$\frac{P}{v}\to \frac{P\prime }{v\prime }=\frac{P}{v}\cdot \frac{D_{\mathit{OS}}+D_{\mathit{US}}}{d_{\mathit{OS}}+d_{\mathit{US}}}$$

wobei y_max jene Stelle ist, bei welcher auf der Ober- und/oder Unterseite des Substarts abhängig von der Position y eine relative Abweichung zwischen gemessener und gewünschter Schichtdicke vorliegt und ihr Maximum bzw. ihren maximal möglichen Wert aufweist.In the next step, the local deviations between the desired layer thicknesses D _OS (y) and/or D _US (y) and the measured layer thicknesses dos(y) and dus(y) are treated. The following relationship is used for this (BB denotes the bandwidth): $$\underset{\mathit{OS},\mathit{US}}{\mathrm{Max}}\underset{0\le y\le \mathit{BB}}{\mathrm{Max}}\left\{\left|1-\frac{D_{\mathit{OS}}\left(y\right)}{d_{\mathit{OS}}\left(y\right)}\right|,\left|1-\frac{D_{\mathit{US}}\left(y\right)}{d_{\mathit{US}}\left(y\right)}\right|\right\}\le \underset{\mathit{OS},\mathit{US}}{\mathrm{Max}}\left\{\left|1-\frac{D_{\mathit{OS}}\left(y_{\mathit{Max}}\right)}{d_{\mathit{OS}}\left(y_{\mathit{Max}}\right)}\right|,\left|1-\frac{D_{\mathit{US}}\left(y_{\mathit{Max}}\right)}{d_{\mathit{US}}\left(y_{\mathit{Max}}\right)}\right|\right\}$$

where y _max is the point at which, on the top and/or bottom side of the substrate, there is a relative deviation between the measured and desired layer thickness depending on the position y and has its maximum or its maximum possible value.

wobei a der kleinste Abstand zwischen Substrat und der substratnächsten Drehachse der Klappe ist.For example, if the point y _max is on the underside of the substrate, first all flap angles a _i with the opening widths b _i are corrected according to their distances maxi to the flap i: $$b_i\to b_i^{\prime }=b_i\cdot {\left(\frac{d_{\mathit{US}}\left(y_{\mathit{Max}}\right)}{D_{\mathit{US}}\left(y_{\mathit{Max}}\right)}\right)}^{{\left(\frac{a}{{\mathit{Max}}_i}\right)}^n}$$

where a is the smallest distance between the substrate and the axis of rotation of the flap closest to the substrate.

If, however, the point y _max is located on the top side of the substrate, first all flap angles α _i with the opening widths b _i on the top side are adjusted according to their distances max _i to flap i: $$b_i\to b_i^{\prime }=b_i.{\left(\frac{d_{\mathit{OS}}\left(y_{\mathit{Max}}\right)}{D_{\mathit{OS}}\left(y_{\mathit{Max}}\right)}\right)}^{{\left(\frac{a}{{\mathit{Max}}_i}\right)}^n}$$

The exponent n with 1 <= n <= 3 is fixed and is optimized through experience so that the described iterative algorithm leads to the desired layer thickness with as few iterations as possible.

To avoid unnecessary adjustment of the flaps, the flap angles are no longer changed as soon as the relative deviation between the desired and measured layer thickness falls below a limit value. The limit value at which the flap setting is no longer changed can, for example, be selected to be less than 5% if the total deviation (i.e. on both sides) is less than 10%.

The invention thus relates to a PVD method for depositing metallic layers from a vapor phase onto a metallic substrate, in particular onto substrates with different bandwidths, wherein at least one evaporator and one substrate are present in a coating unit and there is a flow path for the coating particles between the evaporator and the substrate, wherein in the flow path there is at least one flap per substrate side, which is arranged to be rotatable about an axis of rotation for influencing the flow resistance, wherein the axis of rotation runs parallel to the substrate plane and preferably longitudinally to the transport direction of the substrate.

It is advantageous if the flaps have a flap angle of attack which can be adjusted by means of an adjustment device so that the flaps can be adjusted independently of one another.

It is also advantageous if the flaps work in conjunction with side panels arranged on both sides.

Advantageously, the side panels are designed in one or more parts and can be moved by means of a displacement device to adapt to the respective substrate width.

In an advantageous embodiment, the flaps form a mono-flap (8) or a multi-flap system or a combined flap system.

In a particularly advantageous embodiment, the flaps have flap wings which vary in their length and/or height and/or width, whereby an alternating flap arrangement with flap wings of different lengths is set.

In this case, an arrangement can be selected in which the flap length is shorter at the substrate edge, in particular decreasing steadily towards the substrate edge. The flaps can influence the layer thickness distribution, with longer flaps representing a greater obstacle than shorter flaps.

It is according to the invention if the flaps are arranged symmetrically away from an axis of symmetry towards the substrate edge, so that the flap angle of attack decreases continuously towards the substrate edge.

It is also advantageous if the flap angle of attack on corresponding flaps on the side of the substrate closest to the evaporator is set larger than on the associated flap mirrored over the substrate on the side of the substrate far from the evaporator. Advantageously, those flaps have their axis of rotation further away from the plane of symmetry than half the bandwidth, with the flap angle of attack being set such that the flap blades point directly at the closest substrate edge.

In an advantageous embodiment, after a coating process, the deposited layer thickness is measured in a measuring unit, wherein the adjustment device acts in conjunction with the measuring unit and the adjustment of the flap angle of attack takes place depending on the measurement results.

In a further advantageous embodiment, a strip-shaped substrate is continuously coated in the method.

One embodiment provides that the strip-shaped substrate is guided horizontally or vertically during coating.

One embodiment provides that, in the case of vertical tape guidance, the opposing flaps on both sides of the substrate are positioned mirror-symmetrically. This setting has the advantage that it allows a homogeneous layer thickness to be produced on both sides of the substrate.

One embodiment provides that, when the belt is guided horizontally, the opposing flaps on both sides of the substrate are set at different angles. In an arrangement which positions the evaporator closer to the underside of the substrate than to the top of the substrate, without any regulation, the ratio of the layer thicknesses of the top of the substrate to the underside of the substrate is approximately 1:1.8, which means that a layer almost twice as thick would form on the underside of the substrate. Therefore, the flap setting angle on the side of the substrate near the evaporator can advantageously be set larger than that on the side far from the evaporator, in particular at least 10° larger.

Advantageously, the substrate is a metal strip, in particular a steel strip, and a metallic corrosion protection layer, preferably based on zinc, is deposited as a coating.

The invention also relates to a device for PVD coating of metallic substrates, in particular substrates with different substrate widths, in particular according to a method according to one of the preceding claims, wherein in a coating unit, which is designed in particular as a coating chamber, at least one evaporator is present and between the evaporator and a substrate that can be guided through the coating device there is a flow path for the coating particles, wherein in Flow path has at least one flap per substrate side, which is arranged to rotate about an axis of rotation to influence the flow resistance, wherein the axis of rotation runs parallel to the substrate plane and preferably longitudinally to the transport direction of the substrate.

It is advantageous if the flaps have a flap angle of attack which can be adjusted by means of an adjustment device so that the flaps can be adjusted independently of one another.

In addition, it is advantageous if, in addition to the flaps, two side panels are arranged, one on each side of the substrate.

It is also advantageous if the side panels are designed in one or more parts and can be moved by means of a displacement device to adapt to the respective substrate width.

In an advantageous embodiment, a mono-flap or a multi-flap system or a combined flap system is present in the coating unit.

In a further advantageous embodiment, the flaps have flap wings which vary in their length and/or height and/or width, wherein an alternating flap arrangement with flap wings of different lengths can be set.

According to the invention, the flaps are arranged symmetrically away from an axis of symmetry towards the substrate edge and have a flap angle of attack that steadily decreases towards the substrate edge.

Advantageously, the flap angle of corresponding flaps on the side of the substrate near the evaporator is greater than the flap angle of the associated flap mirrored over the substrate on the side of the substrate far from the evaporator.

It is advantageous if, for those flaps whose axis of rotation is further away from the plane of symmetry than half the bandwidth, the flap angle of attack is set in such a way that the flap blades point directly towards the nearest band edge.

It is also advantageous if a measuring unit is arranged after the coating unit, which is coupled to the adjustment device of the flaps.

In addition, it is advantageous if the at least one coating unit is designed as a chamber with an inlet side and an outlet side, wherein the substrate can be guided from the inlet side to the outlet side and wherein a vacuum lock is present on the inlet side and outlet side, so that a substrate can be continuously guided through the chamber and coated.

One embodiment of the device provides that the device is designed such that the strip-shaped substrate is guided horizontally or vertically in the chamber during coating.

One embodiment of the device provides that, in the case of a vertical tape guide, the opposing flaps on both sides of the substrate are positioned mirror-symmetrically.

One embodiment of the device provides that, when the belt is guided horizontally, the opposing flaps on both sides of the substrate are positioned differently.

Figur 1:

Beschichtungsanlage mit einer horizontalen Substratführung;

Figur 2:

Beschichtungsanlage mit einer horizontalen Substratführung und mehreren nacheinander geschalteten Beschichtungs- und Messeinheiten;

Figur 3:

Multiklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer horizontalen Substratführung;

Figur 4:

Multiklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer horizontalen Substratführung;

Figur 5:

Multiklappensystem angeordnet auf einer Kreisbahn sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer horizontalen Substratführung;

Figur 6:

Multiklappensystem angeordnet auf einer Kreisbahn sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer horizontalen Substratführung;

Figur 7:

Monoklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer horizontalen Substratführung;

Figur 8:

Monoklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer horizontalen Substratführung;

Figur 9:

Beschichtungsanlage mit einer vertikalen Substratführung;

Figur 10:

Multiklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer vertikalen Substratführung;

Figur 11:

Multiklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer vertikalen Substratführung

Figur 12:

Multiklappensystem angeordnet auf einer Kreisbahn sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer vertikalen Substratführung;

Figur 13:

Multiklappensystem angeordnet auf einer Kreisbahn sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer vertikalen Substratführung;

Figur 14:

Monoklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines breiten Substrats bei einer vertikalen Substratführung;

Figur 15:

Monoklappensystem angeordnet auf einer Ebene sowie mehrteilige, seitlich verschiebbare Blenden für Beschichtung eines schmalen Substrats bei einer vertikalen Substratführung;

Figur 16:

Klappensystem zeigend die Parameter, welche bei der Einstellung des Klappenanstellwinkels berücksichtigt werden.

Figur 17:

beispielhafte Beschichtungsverteilung für eine nicht homogene Zielschichtdickenverteilung.

The invention is explained by way of example using a drawing. In the drawing:

Figure 1:

Coating system with a horizontal substrate guide;

Figure 2:

Coating system with a horizontal substrate guide and several coating and measuring units connected one after the other;

Figure 3:

Multi-flap system arranged on one level as well as multi-part, laterally movable panels for coating a wide substrate with a horizontal substrate guide;

Figure 4:

Multi-flap system arranged on one level as well as multi-part, laterally movable panels for coating a narrow substrate with a horizontal substrate guide;

Figure 5:

Multi-flap system arranged on a circular path as well as multi-part, laterally movable panels for coating a wide substrate with a horizontal substrate guide;

Figure 6:

Multi-flap system arranged on a circular path as well as multi-part, laterally movable panels for coating a narrow substrate with a horizontal substrate guide;

Figure 7:

Mono flap system arranged on one level as well as multi-part, laterally movable panels for coating a wide substrate with a horizontal substrate guide;

Figure 8:

Mono flap system arranged on one level as well as multi-part, laterally movable panels for coating a narrow substrate with a horizontal substrate guide;

Figure 9:

Coating system with a vertical substrate guide;

Figure 10:

Multi-flap system arranged on one level as well as multi-part, laterally movable panels for coating a wide substrate with a vertical substrate guide;

Figure 11:

Multi-flap system arranged on one level as well as multi-part, laterally movable panels for coating a narrow substrate with a vertical substrate guide

Figure 12:

Multi-flap system arranged on a circular path as well as multi-part, laterally movable panels for coating a wide substrate with a vertical substrate guide;

Figure 13:

Multi-flap system arranged on a circular path as well as multi-part, laterally movable panels for coating a narrow substrate with a vertical substrate guide;

Figure 14:

Mono flap system arranged on one level as well as multi-part, laterally movable panels for coating a wide substrate with a vertical substrate guide;

Figure 15:

Mono flap system arranged on one level as well as multi-part, laterally movable panels for coating a narrow substrate with a vertical substrate guide;

Figure 16:

Flap system showing the parameters which are taken into account when setting the flap angle of attack.

Figure 17:

Example coating distribution for a non-homogeneous target layer thickness distribution.

The coating process according to the invention is carried out in a coating system 1 ( Figure 1 ), wherein the coating system 1 comprises at least two vacuum locks 2, at least one surface activation device 3, at least one coating unit 4 and at least one measuring unit 5.

Such a coating system 1 can have a horizontal ( Figure 1 ) and/or a vertical ( Figure 9 ) substrate guidance.

In the coating system 1, several coating units 4 and measuring units 5 arranged one behind the other can be provided ( Figure 2 ) so that the layer thickness can be measured locally and adjusted if necessary. The layer thickness can be measured using contactless measuring techniques, such as fluorescence spectroscopy.

The coating unit 4 can be designed like a coating chamber in which at least one evaporator 6 and a flap system comprising several flaps 7 are provided for controlling the steam flow and the steam pressure. The conventional side walls can be replaced by side panels which can act in conjunction with the flaps 7. In addition, the coating unit 4 comprises at least two vacuum locks 2 and an inlet and an outlet side so that the substrate can be continuously introduced and coated.

The evaporator 6 can be arranged on one side or on both sides of the substrate 13 to be coated.

The flaps 7 can be designed as monoflaps 8 or as multiflaps 9, so that a plurality of monoflaps 8 form a monoflap system 10 and a plurality of multiflaps 9 form a multiflap system 11.

It is also possible to combine both systems, so that multi-flaps 9 and mono-flaps 8 exist side by side.

In a multi-flap system 11 ( Figure 3 ) at least two rows of flaps 12 are provided, which are arranged along the conveying direction of the substrate 13 or transversely to the conveying direction of the substrate 13. The axes of the rows of flaps 12 can be located in a plane running parallel to the substrate 13 on the side of the substrate 13 near the evaporator, on the side of the substrate 13 far from the evaporator or on both sides of the substrate 13. In the coating unit 4, one-part or multi-part lateral panels 14 can be provided, which point towards the substrate edge 15 and can be displaced by means of one or more displacement devices 16. The displacement device 16 can be designed like a support arm.

The transverse center 17 of the substrate 13 has an imaginary axis of symmetry 18 which runs transversely to the transport direction of the substrate 13. The flaps 7 are arranged symmetrically away from the axis of symmetry 18 towards the substrate edge 19, so that the flap angle 20 decreases symmetrically by a certain angular size towards the substrate edge 19.

The reference value for the flap angle of attack 20 is the plane spanned by the axes of all shafts 21 of the flaps 7 on the substrate side.

The decrease in the flap angle of attack 20 becomes smaller steadily towards the substrate edge 19, whereby the opening angle of the flap 7 which is arranged closest to the axis of symmetry 18 is, for example, 125°. In an arrangement with 4 flaps 7 per quadrant of the chamber cross-section, the opening angles away from the axis of symmetry 18 could have the following values: 125°, 90°, 60°, 35°. In this In this case, the angle change is 35°, 30° and 25° and therefore decreases towards the edge. If the flap angles of attack are generally designated w ₁ , w ₂ , w ₃ ,..., w _n ascending from the axis of symmetry to the edge, then preferably (w _i+1 - w _i ) should be smaller than (wi- w _i-1 ) and all (w _i+1 - w _i ) should be greater than 5 °, but smaller than (200 / n) °, so that the layer thickness is as constant as possible up to the edge.

The flap angle 20 is variably adjustable depending on the substrate width and the desired layer thickness. The flap angle 20 of the flaps 7 pointing towards the substrate edge 19 decreases with the decreasing substrate width. Those flaps which are arranged outside the substrate 13, i.e. those flaps 7 whose axis of rotation is further away from the plane of symmetry 18 than half the substrate width, can preferably have a flap angle 20 so that the flap wings 22 point directly towards the nearest substrate edge 15. Thus, the flaps 7 pointing towards the substrate edge 19 have a smaller flap angle 20 with a narrow substrate 13 than with a wide substrate 13 ( Figure 4 ). The opening angle of these flap wings 22 is preferably 0°, ie no opening. This setting can increase the layer thickness at the edge of the substrate 13, since the resistance to the flow can be minimized by this setting.

In addition, the flap angle of attack 20 is larger in the region of the transverse center 17 of the substrate 13 and decreases towards the substrate edge 19.

Furthermore, a larger flap angle of attack 20 is set on the side of the substrate 13 close to the evaporator than on the side of the substrate 13 remote from the evaporator.

For adjusting the flap setting angle 20, it is provided to arrange shafts 21 in a coating unit 4, which carry the flaps 7. The shafts 21 can be arranged along the conveying direction of the substrate 13 or transversely to the conveying direction of the substrate 13. Preferably, the shafts 21 are arranged along the conveying direction of the substrate 13 and pass through the entire coating unit 4. The corresponding flaps 7 are arranged rotatably with a longitudinal edge on the shaft 21, which corresponds to an imaginary axis of rotation, and can thus be adjusted with respect to their setting angle 20 to the substrate 13. The axis of rotation runs parallel to the substrate plane and can run transversely or longitudinally to the transport direction of the substrate. An arrangement longitudinally to the transport direction can have structural advantages for the device and can advantageously improve the homogeneity the layer thickness across the substrate width. It is also possible to vary the longitudinal alignment by 5 to 45°, whereby a deviation of plus/minus 5° is still interpreted as essentially longitudinal to the transport direction. A deviation of more than 5°, i.e. a deliberate "slant setting" of the axis of rotation in relation to the transport direction, can represent an alternative embodiment, which can, however, be more challenging in terms of construction. In an arrangement transverse to the transport direction, the flap wings 22 can be designed in several parts in order to be able to influence the homogeneity of the layer thickness across the width of the substrate 13.

If the flaps 7 are perpendicular to the plane of the substrate 13, the flow is subjected to a correspondingly lower resistance. The flaps 7 can have an extension away from the shafts 21 that is so large that, in the case of flaps 7 that are arranged in the plane of the substrate 13, the free longitudinal edges of the flap 7 rest against the next shaft 21 or slightly overlap them, so that certain areas can also be blocked against the flow (e.g. when the substrate is at a standstill). The flap angle 20 is adjusted by means of an adjustment device 23, which can be located outside the coating unit 4. It is advantageous if each flap 7 has its own adjustment device 23.

In a further embodiment, the flap rows 12 can be arranged on an imaginary circular path, parabola or ellipse ( Figure 5 ). Even with such a flap configuration, the flap angle of attack 20 decreases in controlled angular sizes from the axis of symmetry 18 towards the substrate edge 19. This means that the corresponding values are predetermined or specified.

In addition, the flap angle 20 of the flaps 7 pointing towards the substrate edge 19 decreases with the decreasing substrate width. Thus, the flaps 7 pointing towards the substrate edge 19 have a smaller flap angle 20 with a narrow substrate 13 than with a wide substrate 13 ( Figure 6 ).

In a further advantageous embodiment, the flap system can be designed as a mono-flap system 10 ( Figure 7 ). In such a mono-flap system 10, at least two rows of flaps 12 are also provided, which are arranged along the conveying direction of the substrate 13 or transversely to the conveying direction of the substrate 13. The rows of flaps 12 can be located on a plane running parallel to the substrate 13 on the side of the substrate 13 near the evaporator, on the side of the substrate 13 far from the evaporator or on both sides of the substrate 13.

In the mono-flap system 10, the flap rows 12 can also be arranged on an imaginary circular path, parabola or ellipse. Regardless of whether the flap rows are on a plane or on an imaginary circular path, parabola or ellipse, the flaps 7 are arranged symmetrically away from the axis of symmetry 18 towards the substrate 13 and the flap angle of attack 20 decreases symmetrically towards the substrate edge 19 by a certain angular size.

With a wide substrate 13, the flap angle of attack 20 is larger than with a narrow substrate 13 ( Figure 8 ).

Another embodiment provides a coating system 1 with a vertical substrate guide ( Figure 9 ).

Even with a vertical substrate guide, the coating system 1 comprises at least two vacuum locks 2, at least one surface activation device 3, at least one coating unit 4 and at least one measuring unit 5.

The coating unit 4 can be designed like a coating chamber in which at least one evaporator 6 and a flap system comprising several flaps 7 are provided for controlling the steam flow and the steam pressure. The conventional side walls can be replaced by side panels which can act in conjunction with the flaps 7. In addition, the coating unit 4 comprises at least two vacuum locks 2 and an inlet and an outlet side so that the substrate 13 can be continuously introduced vertically and coated.

The evaporator 6 can be arranged on one side or on both sides of the substrate 13 to be coated.

The flaps 7 can be designed as monoflaps 8 or as multiflaps 9, so that a plurality of monoflaps 8 form a monoflap system 10 and a plurality of multiflaps 9 form a multiflap system 11.

Of course, a mixture of both systems is also possible, so that multi-flaps 9 and mono-flaps 8 exist side by side.

In a vertical substrate guide, the substrate 13 is introduced vertically along the Z-axis into the coating unit 4. In one embodiment, two rows of flaps 12 are provided in the coating unit 4, which are arranged on both sides of the substrate 13 on a plane running parallel to the substrate 13. Each row of flaps 12 comprises ten multi-flaps 10, which have a decreasing flap angle 20 away from the axis of symmetry 18. The decrease in the flap angle 20 depends on the substrate width and the desired layer thickness. It is therefore slower with a wide substrate 13 than with a narrow substrate 13 ( Figure 10 ).

For better control of the steam flow and the steam pressure, such a multi-flap system 10 works in combination with side panels 14, which can be made of one or more parts. The side panels 14 are arranged in a rotatable manner, for example, in the middle and/or on the outside. They are adjustable in their angle and can be designed to be horizontally and/or laterally displaceable. The lateral displacement of the side panels 14 is carried out by means of a displacement device 16.

The reduction in the flap angle of attack 20 is greater with a narrow substrate 13, especially with the flaps 7 positioned radially towards the substrate edge 19 ( Figure 11 ). The opening angle of these multi-flaps 9 is preferably 0°, ie no opening. This setting can increase the layer thickness at the edge of the substrate 13, since the resistance to the flow can be minimized by this setting.

In another embodiment, the flap rows 12 can be arranged on an imaginary circular path, parabola or ellipse. Two flap rows 12 are provided and each flap row 12 can comprise ten multi-flaps 9, each of which is formed from two flap wings 22. The flap wings 22 are arranged rotatably on a shaft 21 ( Figure 12 ).

The substrate 13 is introduced vertically along the Z-axis into the coating unit 4. The flap rows 12 are arranged on both sides of the substrate 13. The flap angle 20 is larger in the area of the transverse center 17 of the substrate 13 and increases towards the substrate edge 19. With a wide substrate 13, the decrease in the flap angle of attack 20 is slower than with a narrow substrate 13 ( Figure 13 ).

In a further embodiment with a vertical substrate guide, two rows of flaps 12 are provided, which are arranged on a plane running parallel to the substrate 13 ( Figure 14 ). Each row of flaps 12 comprises ten mono flaps 8, which form a flap system. Lateral baffles 14 are also provided, which serve to control the steam flow and the steam pressure. Even with such a flap configuration, the flap angles 20 decrease in regulated angular sizes from the axis of symmetry 18 towards the substrate edge 19. The decrease in the flap angles 20 is faster with a narrow substrate 13 than with a wide substrate 13 ( Figure 15 ).

In a mono-flap system 10, the flaps 7 are designed as so-called mono-flaps 8. A mono-flap 8 has a flap wing 22 which is rotatably arranged on a shaft 21. The shaft 21 is designed as a double shaft with an inner shaft and an outer hollow shaft. The flap angle of attack 20 is adjusted by actuating the shafts by means of an adjusting device 23.

In a multi-flap system 11, the flaps 7 are designed as so-called multi-flaps 9. Here, two flap wings 22 are arranged on a shaft 21, which is preferably designed as a double shaft with an inner shaft and an outer hollow shaft. This allows one flap wing 22 to be arranged on the inner shaft and one flap wing 22 on the outer hollow shaft.

Thus, both flap wings 22 can be moved and adjusted independently of one another, whereby both the flap angle of attack 20 to the substrate 13 and the angle to one another can be adjusted. It can also be provided that the distance between the shafts 21 to one another corresponds to twice the width of a flap wing 22 or is slightly less.

Preferably, the flaps 7 have an extension such that they pass through the coating unit 4 over the entire length in the transport direction of the substrate 13.

By using the multi-flaps 9, the effective width and the number of degrees of freedom of a flap 7 can be increased. This increases the setting variability of the flap system and thus enables better adaptation to different substrate widths.

The flap wings 22 can be angled independently of one another in the X/Y or Z direction, so that the mono-flap system 10 or the multi-flap system 11 can be changed to any geometric configuration and angular position. Individual flaps 7 in a flap row 12 can also be adjusted independently of one another.

Accordingly, the flaps 7 in a flap system can, for example, have a funnel-shaped or an arrow-shaped configuration within a flap row 12.

In one embodiment, one row of flaps 12 may have the funnel-shaped flap configuration and the other row of flaps 12 may have the arrow-shaped flap configuration.

In a further embodiment, all flap rows 12 can have the same flap configuration.

In addition, the extension of the flap wings 22 can vary in length.

In one embodiment, all flap wings 22 have the same length.

In a further embodiment, the flap wings 22 can be of different lengths. Such a flap system can have long and short flap wings. By using flap wings 22 of different lengths, an alternating flap arrangement within a flap row 12 is possible.

In a mono-flap system 10, short and long mono-flaps 8 can be arranged alternately within a flap row 12.

In a multi-flap system 11, a multi-flap 9 can have a short and a long flap wing 22.

By using flap wings 22 of different lengths, the control of the metal vapor can be separated from the control of the flow rate. The long flap wings 22 primarily serve to control the gas flow, while the short flap wings 22 act as a flow obstacle for adjusting the flow rate. The length of the short flap wings 22 is selected so that the gas flow is maintained even when the flaps 7 are aligned vertically. is not completely prevented. If the flaps 7 are aligned parallel to each other and parallel to the flow direction, the flow rate reaches its maximum value.

The flap system works in combination with the side panels 14, which can be designed in one piece or in multiple pieces. Conventional side walls of a coating unit 4 are replaced by panels. This leads to higher layer thicknesses at the substrate edge 19. In addition, complete sealing off of the substrate 13 by side walls is prevented.

The side panels 14 are arranged so that they can rotate centrally and/or externally, for example. They are adjustable in their angle and can be designed to be horizontally and/or laterally displaceable. The lateral displaceability of the side panels 14 is achieved by, for example, mounting them on support arms that have a corresponding degree of freedom of displacement relative to the substrate 13 and are actuated by a drive.

In an advantageous embodiment, each support arm contains individually controllable drives for adjusting the angle of attack of the lateral panels 14 located thereon.

The use of the side panels 14 leads to an improved uniformity of the layer at the substrate edges 19. This is achieved by damming or shielding effects. In addition, the distance to the substrate 13 can be specifically changed for varying strip widths using linear guides of the side panels 14. The displacement of the side panels 14 by means of support arms has the advantage, compared to a conventional displacement, that no complicated mechanics with linear guides are necessary within the coating unit 4 loaded with the gaseous coating substance.

The parameters that are taken into account when adjusting the flaps are in Figure 16 . Thus, the maximum distance between the axis of rotation of a flap 7 and the substrate 13 is marked with maxi. The smallest distance between the substrate 13 and the axis of rotation of a flap 7 closest to the substrate is marked with a. The opening angle α of a multi-flap 9 consists of the opening angle β of the first flap wing 22a and the opening angle γ of the second flap wing 22b and is marked as the opening width b _i .

Figure 17 shows a possible layer thickness distribution, which varies across the substrate width as well as on each substrate side.

The invention is explained by way of example using an embodiment.

Example

A substrate 13 having a thickness of 1 mm is coated. The substrate 13 is conveyed vertically in the Z direction. The coating unit 4 is equipped with an evaporator 6, two side panels 14 and two rows of flaps 12, each of which comprises six monoflaps 9. The monoflaps 9 close to the evaporator have a funnel-shaped configuration and the monoflaps 9 far from the evaporator have an arrow-shaped configuration.

The particle density directly at the evaporator 6 is 6.6·10 ²⁰ particles/m ³ , while the particle density on the opposite side of the coating unit 4 is 3.9 ·10 ²⁰ particles/m ³ . The particle density on both sides of the substrate 13 is uniform and amounts to 1.42 ·10 ²⁰ particles/m ³ .

The use of such a flap system enables a uniform gas distribution on the side of the substrate 13 near the evaporator and on the side far from the evaporator, so that a homogeneous layer thickness is achieved across the entire width of the substrate. In addition, a high deposition efficiency can be achieved due to the very low particle density. In addition, this can also further reduce the risk of droplet formation on the substrate.

By using the flap system according to the invention in conjunction with the side panels 14, a uniform gas distribution is achieved in the area of the substrate 13, regardless of the position or number of evaporators. This leads to a homogeneous layer thickness across the entire width of the substrate 13. In addition, the reduction in layer thickness at the edge is kept to a minimum.

Furthermore, very low particle densities are achieved in the area of the substrate 13. This increases the process efficiency and reduces the risk of droplet formation.

The flexible adjustment of the flap angle 20 and the side panels 14 enables flexible and quick adaptation to different substrate widths.

The invention thus succeeds in creating an efficient and flexible flap system for the vapor phase deposition of layers on substrates 13 of different widths. According to the invention, the flap system can be used to deposit uniform layers with low flow resistance. In addition, the invention creates a control system that includes lateral apertures 14 for the edge area of the substrate 13 and offers adjustment options for coating substrates 13 of different widths. This enables efficient system utilization.

Claims (15)

1. PVD process for depositing metallic layers from a vapour phase onto metallic substrates, in particular onto substrates with different bandwidths, wherein

   in a coating unit at least one evaporator and one substrate are present and there is a flow path for the coating particles between the evaporator and the substrate,

   characterized in that

   at least one flap (7) per substrate side is present in the flow path, which is rotatably arranged about an axis of rotation to influence the flow resistance, wherein the axis of rotation runs in a plane parallel to the substrate plane (13) and preferably longitudinally to the transport direction of the substrate (13), wherein the flaps (7) are arranged symmetrically away from a symmetry axis (18) towards the substrate edge (19), so that the flap angle of attack (20) decreases continuously towards the substrate edge (19).
2. PVD process according to Claim 1, wherein the flaps (7) have a flap angle of attack (20) that can be adjusted by means of an adjustment apparatus (23), so that the flaps (7) are adjustable independently of one another.
3. PVD process according to Claim 1 or 2, wherein the flaps (7) act in conjunction with lateral blinds (14) arranged on both sides.
4. PVD process according to Claim 3, wherein the lateral blinds (14) are formed in one piece or in multiple pieces and are displaceable by means of a displacement apparatus (16) for adaptation to the respective substrate width.
5. PVD process according to any one of the preceding claims, wherein the flap angle of attack (20) is set to be greater at the corresponding flap of the side of the substrate (13) close to the evaporator than at the associated flap mirrored over the substrate on the side of the substrate (13) distal from the evaporator.
6. PVD process according to any one of the preceding claims, wherein for those flaps whose axis of rotation is further away from the symmetry plane than half the bandwidth, the flap angle of attack (20) is set in such a manner that the flap wings (22) point directly to the nearest substrate edge (15).
7. PVD process according to any one of the preceding claims, wherein after a coating process, the deposited layer thickness is measured in a measuring unit (5), wherein the adjustment apparatus (23) acts in conjunction with the measuring unit (5) and the flap angle of attack (20) is set depending on the measurement results.
8. PVD process according to any one of the preceding claims, characterized in that in a vertical band guide, the opposing flaps are set mirror-symmetrically on both sides of the substrate.
9. PVD process according to any one of Claims 1 to 8, characterized in that in a horizontal band guide, the opposing flaps are set differently on both sides of the substrate, the flap angle of attack of the flaps near the evaporator is preferably greater than that of the flaps distal from the evaporator, preferably at least 10° greater.
10. Device for PVD coating of metallic substrates, in particular of substrates with different substrate widths, in particular according to a process according to any one of the preceding claims,
    characterized in that
    in a coating unit (4) that is designed in particular as a coating chamber, at least one evaporator (6) is present, and between the evaporator (6) and a substrate (13) that can be guided through the coating apparatus, there is a flow path for the coating particles, wherein at least one flap (7) per substrate side is present in the flow path, which is rotatably arranged about an axis of rotation to influence the flow resistance, wherein the axis of rotation lies in a plane parallel to the substrate plane (13) and preferably longitudinally to the transport direction of the substrate (13), wherein the flaps (7) are arranged symmetrically away from a symmetry axis (18) towards the substrate edge (19) and have a flap angle of attack (20) that decreases continuously towards the substrate edge (19).
11. Device according to Claim 10, wherein the flaps (7) have a flap angle of attack (20) that can be adjusted by means of an adjustment apparatus (23), so that the flaps (7) are adjustable independently of one another.
12. Device according to Claim 10 or 11, wherein two lateral blinds (14) are arranged one on either side of the substrate in addition to the flaps (7).
13. Device according to Claim 12, wherein the lateral blinds (14) are formed in one piece or in multiple pieces and are displaceable by means of a displacement apparatus (16) for adaptation to the respective substrate width.
14. Device according to any one of Claims 10 to 13, wherein a measuring unit (5) that is coupled to the adjustment apparatus (23) of the flaps (7) is arranged after the coating unit (4).
15. Device according to any one of Claims 10 to 14, characterized in that in a vertical band guide, the opposing flaps are set mirror-symmetrically on both sides of the substrate.

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